Isothermal and Vertical Sections of the K+∥F-,Br-, MoO42- System

A spatial model is formed for the phase complex of the three-component K+parallel to F-,Br-, MoO42- system using data on the compositions and melting temperatures of two- and three-component eutectics and the KOMPAS 3D software. The model is constructed in the composition-temperature coordinates; its basis is the composition triangle of the system, and the applicate axis corresponds to a temperature range of 500-800 degrees C. The model structure assumes the use of the concept "base geometric element of phase region" in order to understand the geometric structure of spatial diagram, each phase region of which is a local volume with bounded surfaces. Based on the model, liquidus surface isotherms and isothermal and vertical sections are obtained, and the material balance of equilibrium phases is calculated for arbitrary selected representative points of the system. The material balance for an arbitrarily selected representative point of phases, which coexist in equilibrium at a given temperature and within a given temperature range, is shown to be calculated based on the geometry of the constructed 3D model of the system under study. The ratios of the equilibrium phases are calculated using mathematical matrix equations. The 3D models of multicomponent systems (MCSs), which are constructed based on the information about low-dimension elements, allow us to determine whether an invariant composition belongs to a certain simplex without performing experiments. When studying the liquidus surface of MCS, researchers restrict themselves to finding the invariant compositions that solidify at lower temperatures as compared to those of the starting components. However, many manufacturing processes occur in a temperature range. The 3D model and the T-x-y phase diagram of a MCS allows one to select the given temperature range using isothermal and vertical sections. In contrast to traditional methods, the suggested approach is simpler and clearer, which allows its wide application for physicochemical analysis of MCSs.